In many fields of wireless communication, such as microwave communication, waveguides are used for transporting wireless signals, due to the low losses incurred in a waveguide. When mounting or connecting one waveguide section to another section, there is often a gap between the end-points of the sections.
When there is a gap between two waveguide sections in a waveguide arrangement, it has to be bridged to avoid leakage, return loss and transition loss for the electromagnetic field contained within the waveguide arrangement. An opening that allows the electromagnetic field to partly escape the waveguide arrangement affects return loss and transition loss, i.e. both unwanted reflections and losses occur. Today, a resilient ring gasket that comprises conductive material is commonly used. For example, U.S. Pat. No. 4,932,673 describes a gasket that comprises an electrically conductive elastomeric ring filled with metallic particles.
Such solutions work acceptable for frequencies up to about 38 GHz. For higher frequencies, the waveguide dimensions become relatively small and a resilient gasket tends to expand into the waveguide when compressed, changing the waveguide measures, which affects the transmission properties in an undesired manner.
There is thus a need for an improved waveguide gasket that does not affect the transmission properties when compressed.